Catechism of the Catholic Church §1524 — excerpt
In addition to the Anointing of the Sick, the Church offers those who are about to leave this life the Eucharist as viaticum. Communion in the body and blood of Christ, received at this moment of "passing over" to the Father, has a particular significance and importance.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.